If you’re in Delhi, have you noticed the constant haze/dust in the air lately? Well, it’s smog that has enveloped Delhi and this smog is a very common phenomenon in city during the month of October and November i.e. when winter begins to set in. This year too it has brought trouble for Delhiites-especially to those suffering from asthma, high blood pressure and heart conditions as it leads to severe respiratory ailments. Long-term exposure to such atmosphere can even cause lung cancer in some cases.
A 12-day spell of smog was witnessed in Delhi from October 26 to November 8 last year. This time it is expected to last for over a week with a break of 2 to 3 days in between.
Reasons for formation of this smog
Slow wind speed coupled with low temperature and high humidity is the reason behind the formation of smog. This condition does not allow pollutants to spread and thus traps vehicular and industrial pollution making the air very dangerous to breath.
Another reason that aggravates the condition further is farm fire which takes place in neighbouring states of Uttar Pradesh, Haryana and Punjab in late October and early November. The smoke billowing from the paddy stubbles burnt in the farm lands blow in to Delhi and get trapped in the air due to low wind speed creating a situation of smog. Though this practice of burning paddy stubbles is banned, farmers continue to do so as they believe the leftover disease or insects in the stubbles would be eradicated entirely making the soil ready for fresh sowing.
How it will clear
High wind velocity helps to clear smog as it spreads the pollutants to wider areas gradually carrying it away. Another factor that helps in clearing smog is rain. Due to rain, pollutants settle down on the ground clearing up the sky, as the particles tend to stick to the droplets of water while falling down. The reversal of wind pattern from easterly to westerly or northwesterly also helps in clearing smog as this leads to a decrease in humidity levels.
Photo by healthmeup.com
